Amyloid adhesin production in activated sludge is enhanced in lab-scale sequencing batch reactors: Feeding regime impacts microbial community and amyloid distribution
Amyloid adhesins are β-sheet-rich extracellular proteins thought to contribute to bioflocculation. They are present in activated sludge to varying extent. However, it remains unclear which operational conditions promote their production. To this end, the abundance and distribution of amyloids and th...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2022-12-01
|
| Series: | Water Research X |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2589914722000329 |
| _version_ | 1811298295100735488 |
|---|---|
| author | An-Sofie Christiaens Manon Van Steenkiste Koen Rummens Ilse Smets |
| author_facet | An-Sofie Christiaens Manon Van Steenkiste Koen Rummens Ilse Smets |
| author_sort | An-Sofie Christiaens |
| collection | DOAJ |
| description | Amyloid adhesins are β-sheet-rich extracellular proteins thought to contribute to bioflocculation. They are present in activated sludge to varying extent. However, it remains unclear which operational conditions promote their production. To this end, the abundance and distribution of amyloids and their potential producers were monitored in two lab-scale reactors operated in sequencing batch mode with an unaerated and aerated reaction phase. Various feeding regimes ranging from feast-famine to nearly continuous feeding were applied. Thioflavin T staining revealed more amyloids in the lab-scale reactors during all operational stages compared to the full-scale industrial and municipal inocula. Furthermore, the feeding regime impacted the distribution of produced amyloids from dense clusters during feast-famine conditions towards a dispersed distribution during nearly continuous feeding. This dispersed presence did not negatively impact the bioflocculation (towards average floc size and shear sensitivity). 16S rRNA sequencing detected several known EPS and amyloid producers. More continuous and, hence, partially aerobic feeding promoted the relative abundance of denitrifiers. Sequential Thioflavin T staining and fluorescence in situ hybridization identified Zoogloea and Ca. Competibacter as potential amyloid producers under the applied conditions. This experiment confirms that amyloid producers need to be triggered for production and that the feeding regime impacts the microbial community composition, which in turn influences the amyloid production and distribution. |
| first_indexed | 2024-04-13T06:17:24Z |
| format | Article |
| id | doaj.art-9bdeb61de60d4cf48bf6893b57e4585b |
| institution | Directory Open Access Journal |
| issn | 2589-9147 |
| language | English |
| last_indexed | 2024-04-13T06:17:24Z |
| publishDate | 2022-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Water Research X |
| spelling | doaj.art-9bdeb61de60d4cf48bf6893b57e4585b2022-12-22T02:58:47ZengElsevierWater Research X2589-91472022-12-0117100162Amyloid adhesin production in activated sludge is enhanced in lab-scale sequencing batch reactors: Feeding regime impacts microbial community and amyloid distributionAn-Sofie Christiaens0Manon Van Steenkiste1Koen Rummens2Ilse Smets3KU Leuven, Chemical Engineering Department, Chemical and Biochemical Reactor Engineering and Safety (CREaS), Celestijnenlaan 200f box 2424, Heverlee 3001, BelgiumKU Leuven, Chemical Engineering Department, Chemical and Biochemical Reactor Engineering and Safety (CREaS), Celestijnenlaan 200f box 2424, Heverlee 3001, BelgiumKU Leuven, Chemical Engineering Department, Chemical and Biochemical Reactor Engineering and Safety (CREaS), Celestijnenlaan 200f box 2424, Heverlee 3001, BelgiumCorresponding author.; KU Leuven, Chemical Engineering Department, Chemical and Biochemical Reactor Engineering and Safety (CREaS), Celestijnenlaan 200f box 2424, Heverlee 3001, BelgiumAmyloid adhesins are β-sheet-rich extracellular proteins thought to contribute to bioflocculation. They are present in activated sludge to varying extent. However, it remains unclear which operational conditions promote their production. To this end, the abundance and distribution of amyloids and their potential producers were monitored in two lab-scale reactors operated in sequencing batch mode with an unaerated and aerated reaction phase. Various feeding regimes ranging from feast-famine to nearly continuous feeding were applied. Thioflavin T staining revealed more amyloids in the lab-scale reactors during all operational stages compared to the full-scale industrial and municipal inocula. Furthermore, the feeding regime impacted the distribution of produced amyloids from dense clusters during feast-famine conditions towards a dispersed distribution during nearly continuous feeding. This dispersed presence did not negatively impact the bioflocculation (towards average floc size and shear sensitivity). 16S rRNA sequencing detected several known EPS and amyloid producers. More continuous and, hence, partially aerobic feeding promoted the relative abundance of denitrifiers. Sequential Thioflavin T staining and fluorescence in situ hybridization identified Zoogloea and Ca. Competibacter as potential amyloid producers under the applied conditions. This experiment confirms that amyloid producers need to be triggered for production and that the feeding regime impacts the microbial community composition, which in turn influences the amyloid production and distribution.http://www.sciencedirect.com/science/article/pii/S2589914722000329Biological wastewater treatmentBioflocculationExtracellular polymeric substancesThioflavin TCLSMMicrobial community |
| spellingShingle | An-Sofie Christiaens Manon Van Steenkiste Koen Rummens Ilse Smets Amyloid adhesin production in activated sludge is enhanced in lab-scale sequencing batch reactors: Feeding regime impacts microbial community and amyloid distribution Water Research X Biological wastewater treatment Bioflocculation Extracellular polymeric substances Thioflavin T CLSM Microbial community |
| title | Amyloid adhesin production in activated sludge is enhanced in lab-scale sequencing batch reactors: Feeding regime impacts microbial community and amyloid distribution |
| title_full | Amyloid adhesin production in activated sludge is enhanced in lab-scale sequencing batch reactors: Feeding regime impacts microbial community and amyloid distribution |
| title_fullStr | Amyloid adhesin production in activated sludge is enhanced in lab-scale sequencing batch reactors: Feeding regime impacts microbial community and amyloid distribution |
| title_full_unstemmed | Amyloid adhesin production in activated sludge is enhanced in lab-scale sequencing batch reactors: Feeding regime impacts microbial community and amyloid distribution |
| title_short | Amyloid adhesin production in activated sludge is enhanced in lab-scale sequencing batch reactors: Feeding regime impacts microbial community and amyloid distribution |
| title_sort | amyloid adhesin production in activated sludge is enhanced in lab scale sequencing batch reactors feeding regime impacts microbial community and amyloid distribution |
| topic | Biological wastewater treatment Bioflocculation Extracellular polymeric substances Thioflavin T CLSM Microbial community |
| url | http://www.sciencedirect.com/science/article/pii/S2589914722000329 |
| work_keys_str_mv | AT ansofiechristiaens amyloidadhesinproductioninactivatedsludgeisenhancedinlabscalesequencingbatchreactorsfeedingregimeimpactsmicrobialcommunityandamyloiddistribution AT manonvansteenkiste amyloidadhesinproductioninactivatedsludgeisenhancedinlabscalesequencingbatchreactorsfeedingregimeimpactsmicrobialcommunityandamyloiddistribution AT koenrummens amyloidadhesinproductioninactivatedsludgeisenhancedinlabscalesequencingbatchreactorsfeedingregimeimpactsmicrobialcommunityandamyloiddistribution AT ilsesmets amyloidadhesinproductioninactivatedsludgeisenhancedinlabscalesequencingbatchreactorsfeedingregimeimpactsmicrobialcommunityandamyloiddistribution |